9,019 results match your criteria fluorescently labeled

Treatment of Parkinson's disease in Zebrafish model with a berberine derivative capable of crossing blood brain barrier, targeting mitochondria, and convenient for bioimaging experiments.

Comp Biochem Physiol C Toxicol Pharmacol 2021 Jul 31:109151. Epub 2021 Jul 31.

Biology Institute, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250103, Shandong Province, China; Engineering Research Center of Zebrafish Models for Human Diseases and Drug Screening of Shandong Province, Jinan 250103, Shandong Province, China. Electronic address:

Berberine is a famous alkaloid extracted from Berberis plants and has been widely used as medications and functional food additives. Recent studies reveal that berberine exhibits neuroprotective activity in animal models of Parkinson's disease (PD), the second most prevalent neurodegenerative disorders all over the world. However, the actual site of anti-PD action of berberine remains largely unknown. Read More

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Uptake and translocation of nano/microplastics by rice seedlings: Evidence from a hydroponic experiment.

J Hazard Mater 2021 Jul 21;421:126700. Epub 2021 Jul 21.

College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, Shandong Province 266042, PR China. Electronic address:

Microplastics (MPs) are emerging contaminants in terrestrial systems that cause diverse impacts on plants. However, little is known about whether MPs especially micro-sized MPs can be accumulated and translocated in plants particularly food crops. Hereby, a hydroponic experiment was conducted to verify whether nano-sized (80 nm) and micro-sized (1 µm) fluorescently labeled polystyrene (PS) microspheres can enter rice roots and translocate to aerial parts. Read More

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A workflow for streamlined acquisition and correlation of serial regions of interest in array tomography.

BMC Biol 2021 Jul 30;19(1):152. Epub 2021 Jul 30.

KU Leuven Department of Neurosciences, Leuven Brain Institute, O&N5 Herestraat 49 box 602, 3000, Leuven, Belgium.

Background: Array tomography (AT) is a high-resolution imaging method to resolve fine details at the organelle level and has the advantage that it can provide 3D volumes to show the tissue context. AT can be carried out in a correlative way, combing light and electron microscopy (LM, EM) techniques. However, the correlation between modalities can be a challenge and delineating specific regions of interest in consecutive sections can be time-consuming. Read More

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Polymer ligand binding to surface-immobilized gold nanoparticles: a fluorescence-based study on the adsorption kinetics.

Soft Matter 2021 Jul 29. Epub 2021 Jul 29.

Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.

We report on a simple, fluorescence-based method for the investigation of the binding kinetics of polystyrene ligands, dispersed in an organic solvent, to substrate supported gold nanoparticles. For this purpose, we develop a protocol for the immobilization of gold nanoparticles on glass substrates, that yields sub-monolayers of randomly distributed particles with excellent homogeneity and reproducibility. Using fluorescently labeled polystyrene, we monitor the ligand concentration in bulk dispersion in real time and follow the binding to the particle-decorated substrates. Read More

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Integrin activation is an essential component of SARS-CoV-2 infection.

bioRxiv 2021 Jul 21. Epub 2021 Jul 21.

Cellular entry of coronaviruses depends on binding of the viral spike (S) protein to a specific cellular receptor, the angiotensin-converting enzyme 2 (ACE2). Furthermore, the viral spike protein expresses an RGD motif, suggesting that cell surface integrins may be attachment co-receptors. However, using infectious SARS-CoV-2 requires a biosafety level 3 laboratory (BSL-3), which limits the techniques that can be used to study the mechanism of cell entry. Read More

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Extracellular NLRP3 inflammasome particles are internalized by human coronary artery smooth muscle cells and induce pro-atherogenic effects.

Sci Rep 2021 Jul 26;11(1):15156. Epub 2021 Jul 26.

Klinik und Poliklinik für Kardiologie, Universitätsklinikum Leipzig, Leipzig University, Johannisallee 30, 04103, Leipzig, Germany.

Inflammation driven by intracellular activation of the NLRP3 inflammasome is involved in the pathogenesis of a variety of diseases including vascular pathologies. Inflammasome specks are released into the extracellular compartment from disrupting pyroptotic cells. The potential uptake and function of extracellular NLRP3 inflammasomes in human coronary artery smooth muscle cells (HCASMC) are unknown. Read More

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PEGylation of Guanidinium and Indole Bearing Poly(methacrylamide)s - Biocompatible Terpolymers for pDNA Delivery.

Macromol Biosci 2021 Jul 26:e2100146. Epub 2021 Jul 26.

Institute of Organic Chemistry and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Lessingstrasse 8, Jena, 07743, Germany.

This study describes the first example for shielding of a high performing terpolymer that consists of N-(2-hydroxypropyl)methacrylamide (HPMA), N-(3-guanidinopropyl)methacrylamide (GPMA), and N-(2-indolethyl)methacrylamide monomers (IEMA) by block copolymerization of a polyethylene glycol derivative - poly(nona(ethylene glycol)methyl ether methacrylate) (P(MEO MA)) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The molecular weight of P(MEO MA) is varied from 3 to 40 kg mol while the comonomer content of HPMA, GPMA, and IEMA is kept comparable. The influence of P(MEO MA) block with various molecular weights is investigated over cytotoxicity, plasmid DNA (pDNA) binding, and transfection efficiency of the resulting polyplexes. Read More

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Visualization of Gut Microbiota-host Interactions via Fluorescence In Situ Hybridization, Lectin Staining, and Imaging.

J Vis Exp 2021 Jul 9(173). Epub 2021 Jul 9.

School of Biomedical Engineering, University of British Columbia; Department of Microbiology and Immunology, University of British Columbia; Humans and the Microbiome Program, Canadian Institute for Advanced Research (CIFAR);

Measuring the localization of microbes within their in vivo context is an essential step in revealing the functional relationships between the microbiota and the vertebrate gut. The spatial landscape of the gut microbiota is tightly controlled by physical features - intestinal mucus, crypts, and folds - and is affected by host-controlled properties such as pH, oxygen availability, and immune factors. These properties limit the ability of commensal microbes and pathogens alike to colonize the gut stably. Read More

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The coding microsatellite mutation profile of PMS2-deficient colorectal cancer.

Exp Mol Pathol 2021 Jul 21:104668. Epub 2021 Jul 21.

Department of Applied Tumor Biology, Institute of Pathology, University Hospital Heidelberg, Cooperation Unit Applied Tumor Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Molecular Medicine Partnership Unit (MMPU), University Hospital Heidelberg, Heidelberg, Germany.

Lynch syndrome (LS) is caused by a pathogenic heterozygous germline variant in one of the DNA mismatch repair (MMR) genes: MLH1, MSH2, MSH6 or PMS2. LS-associated colorectal carcinomas (CRCs) are characterized by MMR deficiency and by accumulation of multiple insertions/deletions at coding microsatellites (cMS). MMR deficiency-induced variants at defined cMS loci have a driver function and promote tumorigenesis. Read More

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Multispectral intravital microscopy for simultaneous bright-field and fluorescence imaging of the microvasculature.

Appl Microsc 2021 Jul 24;51(1):12. Epub 2021 Jul 24.

Department of Medical Biophysics, Western University, London, ON, N6A 5C1, Canada.

Intravital video microscopy permits the observation of microcirculatory blood flow. This often requires fluorescent probes to visualize structures and dynamic processes that cannot be observed with conventional bright-field microscopy. Conventional light microscopes do not allow for simultaneous bright-field and fluorescent imaging. Read More

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Internalization of Neutrophil-Derived Microvesicles Modulates TNFα-Stimulated Proinflammatory Cytokine Production in Human Fibroblast-Like Synoviocytes.

Int J Mol Sci 2021 Jul 10;22(14). Epub 2021 Jul 10.

Osteoarthritis and Musculoskeleton Research Unit, Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.

Neutrophil-derived microvesicles (NDMVs) have the potential to exert anti-inflammatory effects. Our study aimed to explore the effects of NDMVs on proinflammatory cytokines expressed by tumor necrosis factor α (TNFα)-stimulated fibroblast-like synoviocytes (FLS). FLS were isolated from the synovium of knee osteoarthritis (OA) patients undergoing surgery. Read More

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Tracking single particles for hours via continuous DNA-mediated fluorophore exchange.

Nat Commun 2021 07 21;12(1):4432. Epub 2021 Jul 21.

Max Planck Institute of Biochemistry, Martinsried, Germany.

Monitoring biomolecules in single-particle tracking experiments is typically achieved by employing fixed organic dyes or fluorescent fusion proteins linked to a target of interest. However, photobleaching typically limits observation times to merely a few seconds, restricting downstream statistical analysis and observation of rare biological events. Here, we overcome this inherent limitation via continuous fluorophore exchange using DNA-PAINT, where fluorescently-labeled oligonucleotides reversibly bind to a single-stranded DNA handle attached to the target molecule. Read More

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Pore-forming alpha-hemolysin efficiently improves the immunogenicity and protective efficacy of protein antigens.

PLoS Pathog 2021 Jul 21;17(7):e1009752. Epub 2021 Jul 21.

National Engineering Research Center of Immunological Products & Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China.

Highly immunogenic exotoxins are used as carrier proteins because they efficiently improve the immunogenicity of polysaccharides. However, their efficiency with protein antigens remains unclear. In the current study, the candidate antigen PA0833 from Pseudomonas aeruginosa was fused to the α-hemolysin mutant HlaH35A from Staphylococcus aureus to form a HlaH35A-PA0833 fusion protein (HPF). Read More

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Biodegradable and Dual-Responsive Polypeptide-Shelled Cyclodextrin-Containers for Intracellular Delivery of Membrane-Impermeable Cargo.

Adv Sci (Weinh) 2021 Jul 18:e2100694. Epub 2021 Jul 18.

Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Muenster, Von-Esmarch-Str. 56, Münster, 48149, Germany.

The transport of membrane impermeable compounds into cells is a prerequisite for the efficient cellular delivery of hydrophilic and amphiphilic compounds and drugs. Transport into the cell's cytosolic compartment should ideally be controllable and it should involve biologically compatible and degradable vehicles. Addressing these challenges, nanocontainers based on cyclodextrin amphiphiles that are stabilized by a biodegradable peptide shell are developed and their potential to deliver fluorescently labeled cargo into human cells is analyzed. Read More

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Imaging of type I procollagen biosynthesis in cells reveals biogenesis in highly organized bodies; Collagenosomes.

Matrix Biol Plus 2021 Dec 23;12:100076. Epub 2021 Jun 23.

Keck School of Medicine of University of Southern California, 1450 Biggy Street, NRT 4510, Los Angeles, CA 90033, USA.

Mechanistic aspects of type I procollagen biosynthesis in cells are poorly understood. To provide more insight into this process we designed a system to directly image type I procollagen biogenesis by co-expression of fluorescently labeled full size procollagen α1(I) and one α2(I) polypeptides. High resolution images show that collagen α1(I) and α2(I) polypeptides are produced in coordination in discrete structures on the ER membrane, which we termed the collagenosomes. Read More

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December 2021

In Vivo Characterization of Endogenous Cardiovascular Extracellular Vesicles in Larval and Adult Zebrafish.

Arterioscler Thromb Vasc Biol 2021 Jul 15:ATVBAHA121316539. Epub 2021 Jul 15.

School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Sciences, University of Bristol, United Kingdom. (A.S., M.B., C.T., J.L., D.P., R.J.R.).

Objective: Extracellular vesicles (EVs) facilitate molecular transport across extracellular space, allowing local and systemic signaling during homeostasis and in disease. Extensive studies have described functional roles for EV populations, including during cardiovascular disease, but the in vivo characterization of endogenously produced EVs is still in its infancy. Because of their genetic tractability and live imaging amenability, zebrafish represent an ideal but under-used model to investigate endogenous EVs. Read More

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Entropic barrier of topologically immobilized DNA in hydrogels.

Proc Natl Acad Sci U S A 2021 Jul;118(28)

Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA 01003

The single most intrinsic property of nonrigid polymer chains is their ability to adopt enormous numbers of chain conformations, resulting in huge conformational entropy. When such macromolecules move in media with restrictive spatial constraints, their trajectories are subjected to reductions in their conformational entropy. The corresponding free energy landscapes are interrupted by entropic barriers separating consecutive spatial domains which function as entropic traps where macromolecules can adopt their conformations more favorably. Read More

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p52Shc regulates the sustainability of ERK activation in a RAF-independent manner.

Mol Biol Cell 2021 Jul 14:mbcE21010007. Epub 2021 Jul 14.

Cellular Informatics Lab, RIKEN, Wako, Saitama, Japan.

p52SHC (SHC) and GRB2 are adaptor proteins involved in the RAS/MAPK (ERK) pathway mediating signals from cell-surface receptors to various cytoplasmic proteins. To further examine their roles in signal transduction, we studied the translocation of fluorescently-labeled SHC and GRB2 to the cell surface, caused by the activation of ERBB receptors by heregulin (HRG). We simultaneously evaluated activated ERK translocation to the nucleus. Read More

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fiducial markers for 3D correlative cryo-fluorescence and FIB-SEM imaging.

iScience 2021 Jul 10;24(7):102714. Epub 2021 Jun 10.

Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.

Imaging of cells and tissues has improved significantly over the last decade. Dual-beam instruments with a focused ion beam mounted on a scanning electron microscope (FIB-SEM), offering high-resolution 3D imaging of large volumes and fields-of-view are becoming widely used in the life sciences. FIB-SEM has most recently been implemented on fully hydrated, cryo-immobilized, biological samples. Read More

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Fluorescent labeling of the root cap cells with the bioactive NBD-S chemical probe based on the cellulose biosynthesis inhibition herbicides.

Biochem Biophys Rep 2021 Sep 29;27:101063. Epub 2021 Jun 29.

Research Laboratory for Biotechnology and Biochemistry (RLABB), Kathmandu, Nepal.

Development of the methods to examine the molecular targets of biologically active compounds is one of the most important subjects in experimental biology/biochemistry. To evaluate the usability of the (7-nitro-2,1,3-benzoxadiazole)-thioether (NBD-S) probe for this purpose, bioactive chemical probe (1) as the cellulose biosynthesis (CB) inhibitor was synthesized and tested. As a result, a variety of fluorescently-labeled particles and organelles were found in the columella root cap cells of radish plants. Read More

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September 2021

Completing the canvas: advances and challenges for DNA-PAINT super-resolution imaging.

Trends Biochem Sci 2021 Jul 8. Epub 2021 Jul 8.

Department of BioNanoScience, Kavli Institute of Nanoscience, Delft University of Technology, van der Maasweg 9, 2629HZ Delft, The Netherlands. Electronic address:

Single-molecule localization microscopy (SMLM) is a potent tool to examine biological systems with unprecedented resolution, enabling the investigation of increasingly smaller structures. At the forefront of these developments is DNA-based point accumulation for imaging in nanoscale topography (DNA-PAINT), which exploits the stochastic and transient binding of fluorescently labeled DNA probes. In its early stages the implementation of DNA-PAINT was burdened by low-throughput, excessive acquisition time, and difficult integration with live-cell imaging. Read More

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The Antimicrobial Activity of the Glycocin Sublancin Is Dependent on an Active Phosphoenolpyruvate-Sugar Phosphotransferase System.

ACS Infect Dis 2021 Jul 9. Epub 2021 Jul 9.

Antimicrobial resistance is a global challenge that is compounded by the limited number of available targets. Glycocins are antimicrobial glycopeptides that are believed to have novel targets. Previous studies have shown that the mechanism of action of the glycocin sublancin 168 involves the glucose uptake system. Read More

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Acoustofluidic device for acoustic capture of Bacillus anthracis spore analogues at low concentration.

J Acoust Soc Am 2021 06;149(6):4228

Mechatronics, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.

A portable device for the rapid concentration of Bacillus subtilis var niger spores, also known as Bacillus globigii (BG), using a thin-reflector acoustofluidic configuration is described. BG spores form an important laboratory analog for the Bacillus anthracis spores, a serious health and bioterrorism risk. Existing systems for spore detection have limitations on detection time and detection that will benefit from the combination with this technology. Read More

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Hyaluronic-Coated Albumin Nanoparticles for the Non-Invasive Delivery of Apatinib in Diabetic Retinopathy.

Int J Nanomedicine 2021 2;16:4481-4494. Epub 2021 Jul 2.

Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.

Purpose: Apatinib (Apa) is a novel anti-vascular endothelial growth factor with the potential to treat diabetic retinopathy (DR); a serious condition leading to visual impairment and blindness. DR treatment relies on invasive techniques associated with various complications. Investigating topical routes for Apa delivery to the posterior eye segment is thus promising but also challenging due to ocular barriers. Read More

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Advances in the creation of animal models of paroxysmal nocturnal hemoglobinuria.

Hematology 2021 Dec;26(1):491-496

Department of Hematology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China.

Paroxysmal nocturnal hemoglobinuria (PNH) is a disease caused by a phosphatidylinositol glycan anchor biosynthesis class A () mutation in hematopoietic stem cells. There are three theories about the possible mechanism of the pathogenesis of PNH: immune escape, anti-apoptotic mechanism, and secondary gene mutation. There has been little gain in the knowledge regarding its pathogenesis during the last decade owing to the lack of representative cell lines and animal models. Read More

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December 2021

Fast Mek1 Hit Identification with TRIC Technology Correlates Well with Other Biophysical Methods.

SLAS Discov 2021 Jul 8:24725552211026267. Epub 2021 Jul 8.

Application Team, NanoTemper Technologies GmbH, Munich, Germany.

The variety and complexity of drug targets are expanding rapidly. At the same time, there is significant interest in exploring a larger chemical space to identify new candidates. Fragment-based screening (FBS) has emerged as a popular alternative to traditional high-throughput screening campaigns to identify such drug candidates. Read More

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Characterizing the Secretion Systems of Magnaporthe oryzae.

Methods Mol Biol 2021 ;2356:69-77

Department of Plant Pathology, Kansas State University, Manhattan, KS, USA.

Pharmacological approaches have made a tremendous impact on the field of microbial secretion systems. This protocol describes the inhibition of Golgi-dependent secretion in Magnaporthe oryzae though brefeldin A (BFA) treatment. State-of-the-art live-cell imaging allows tracking secreted proteins in their secretion pathways. Read More

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January 2021

Mesenchymal Stem Cell (MSC)-Derived Extracellular Vesicles Protect from Neonatal Stroke by Interacting with Microglial Cells.

Neurotherapeutics 2021 Jul 7. Epub 2021 Jul 7.

Department of Neurology, UCSF, 675 Nelson Rising Lane, San Francisco, CA, 94158-0663, USA.

Mesenchymal stem cell (MSC)-based therapies are beneficial in models of perinatal stroke and hypoxia-ischemia. Mounting evidence suggests that in adult injury models, including stroke, MSC-derived small extracellular vesicles (MSC-sEV) contribute to the neuroprotective and regenerative effects of MSCs. Herein, we examined if MSC-sEV protect neonatal brain from stroke and if this effect is mediated via communication with microglia. Read More

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Mixing Matrix-corrected Whole-body Pharmacokinetic Modeling Using Longitudinal Micro-computed Tomography and Fluorescence-mediated Tomography.

Mol Imaging Biol 2021 Jul 6. Epub 2021 Jul 6.

Institute for Experimental Molecular Imaging, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University Clinic, 52074, Aachen, Germany.

Purpose: Pharmacokinetic modeling can be applied to quantify the kinetics of fluorescently labeled compounds using longitudinal micro-computed tomography and fluorescence-mediated tomography (μCT-FMT). However, fluorescence blurring from neighboring organs or tissues and the vasculature within tissues impede the accuracy in the estimation of kinetic parameters. Contributions of elimination and retention activities of fluorescent probes inside the kidneys and liver can be hard to distinguish by a kinetic model. Read More

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A real-time fluorescence assay for CPSF73, the nuclease for pre-mRNA 3'-end processing.

RNA 2021 Jul 6. Epub 2021 Jul 6.

Columbia University

CPSF73 is the endonuclease that catalyzes the cleavage reaction for 3'-end processing of mRNA precursors (pre-mRNAs) in two distinct machineries, a canonical machinery for the majority of pre-mRNAs and a U7 snRNP (U7 machinery) for replication-dependent histone pre-mRNAs in animal cells. CPSF73 also possesses 5'-3' exonuclease activity in the U7 machinery, degrading the downstream cleavage product after the endonucleolytic cleavage. Recent studies show that CPSF73 is a potential target for developing anticancer and antimalarial, antiprotozoal drugs, spurring interest in identifying new small-molecule inhibitors against this enzyme. Read More

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